The invention relates to a fuel filter to be attached to a suction side of a fuel pump provided in a fuel tank.
It has generally been practiced that a bag filter or bag shape filter made of a filtration cloth is provided on a suction side of a fuel pump disposed in a fuel tank, and fuel filtrated and taken into the bag shape filter is supplied to an engine through the fuel pump.
However, in case the filter formed of the bag shape member made of the filtration cloth is provided on the suction side of the fuel pump and the fuel filtrated and taken into the bag shape member is supplied to the engine through the fuel pump, a portion of the bag shape member facing a suction port communicating with the fuel pump and opened inside the bag shape member is sucked toward the suction port, so that the suction port is closed by the portion of the bag shape member to thereby impair the suction ability of the fuel pump.
In view of the above defects, there has been practiced that a plurality of bar members or bag shape members is provided to project toward the inside of the bag shape member from an opening edge portion of the suction port of the bag shape member, so that a portion of the bag shape member located in front of the suction port is supported by the forward edges of the bar shape members when the portion of the bag shape member is moved toward the suction port side upon suction by the fuel pump.
However, the filter having the bar shape members projecting from the opening edge portion of the suction port of the bag shape member for supporting the portion of the bag shape member facing the suction port thereof is useful in case the bag shape member constituting the filter has an enough space between the suction port side and the portion of the bag shape member facing thereto, in other words, in case there is a space for allowing the fuel to properly flow from a side portion between the portion of the bag shape member sacked toward the suction port and the suction port upon sucking action of the fuel pump. However, in case a relatively large space can not be formed between the suction port side and the portion of the bag shape member facing thereto, the filter of this type is not always practical.
In view of the above, it is an object of the present invention to provide a fuel filter, wherein even if a space between an opening surface of a cylindrical portion opened inside a bag shape member communicating with a sucking side of a fuel pump and an inner surface of the bag shape member facing the opening surface is small, a suction ability of the fuel pump can not be impaired.
It is another object of the invention to provide a fuel filter as stated above, which can be made compact and allow fuel to pass all around the fuel filter.
It is a further object of the invention to provide a fuel filter as stated above, which allows the fuel pump to be positioned close to the inner bottom surface of the fuel tank.
Further objects and advantages of the invention will be apparent from the following description of the invention.
A fuel filter according to one aspect of the invention is provided to a sucking side of a fuel pump disposed in a fuel tank. The fuel filter includes a bag member or bag shape member made of a filtration cloth, a cylindrical portion provided to the bag shape member to communicate the suction side of the fuel pump with an interior of the bag shape member, and a shape keeping frame for the bag shape member extending from an inner side of the cylindrical portion inside the bag shape member to the inside of the bag shape member. Further, the fuel filter includes a plate shape portion located in front of an opening of the cylindrical portion in the bag shape member to make a surface contact with an inner surface of the bag shape member in front of the opening.
In the fuel filter thus structured, when the fuel in the fuel tank is sucked into the bag shape member upon suction of the fuel in the bag shape member through operation of the fuel pump, the portion of the bag shape member located in front of the opening of the cylindrical portion is surfacewisely received or horizontally supported by the plate shape portion disposed in front of the opening, so that a passage for guiding, without any resistance, the fuel sucked into the bag shape member is formed between the opening and the plate shape portion in front of the opening, and the fuel is supplied to the fuel pump through the passage.
A fuel filter according to a second aspect of the invention to attain the aforementioned objects has a feature such that, in the fuel filter as described in the first aspect, the bag shape member has a flat shape so that the bag shape member can be provided along a lower surface side of an inner bottom surface of the fuel tank.
In the fuel filter thus structured, in addition to the aforementioned features, further, even if a space between the opening as the suction port of the fuel pump disposed in the fuel tank and an inner bottom surface of the fuel tank is relatively narrow, the fuel filter can be provided to the suction side of the fuel pump.
Further, a fuel filter according to a third aspect of the invention to attain the aforementioned objects has a feature such that, in the fuel filter relating to the first and second aspects, the plate shape portion is provided with holes for allowing the fuel to pass through.
In the fuel filter thus structured, in addition to the aforementioned features, the fuel can also be sucked from the portion of the bag shape member which contacts the plate shape portion located in front of the opening of the cylindrical portion.
Also, a fuel filter according to a fourth aspect of the invention to attain the aforementioned objects has a feature such that, in the fuel filter relating to the first, second and third aspects, the shape keeping frame includes a plurality of bar shape portions extending radially outwardly from a center thereof.
In the fuel filter thus structured, in addition to the aforementioned features, further, the fuel sucked into the bag shape member can be properly guided toward the center thereof.
Furthermore, a fuel filter according to a fifth aspect of the invention to attain the aforementioned objects has features such that, in the fuel filter relating to the first, second and third aspects, the shape keeping frame includes a ring portion; a central plate shape portion disposed at about a center of the ring portion away from the opening of the cylindrical portion; the plate shape portion connected to the central plate shape portion; bar shape portions provided between the ring portion and the central plate shape portion or the plate shape portion and extending radially inwardly of the ring portion. The ring portion and the bar shape portions are provided with abutting pieces projecting to a direction opposite to the cylindrical portion.
In the fuel filter thus structured, in addition to the aforementioned features, further, the fuel sucked into the bag shape member is properly guided toward the cylindrical portion.
Furthermore, a fuel filter according to a sixth aspect of the invention to attain the aforementioned objects has features such that, in the fuel filter relating to the first, second, third, fourth and fifth aspects, the shape keeping frame includes the plate shape portion, and, the plate shape portion is disposed in front of the cylindrical portion away from the opening thereof by a space holding device.
In the fuel filter thus structured, in addition to the aforementioned features, further, the plate shape portion disposed in front of the opening of the cylindrical portion is held with a predetermined space between the opening side and itself even if the fuel pump is actuated, so that the fuel passage can be surely established between the plate shape portion and the opening of the cylindrical portion.
Furthermore, a fuel filter according to a seventh aspect of the invention to attain the aforementioned objects has features such that, in the fuel filter relating to the sixth aspect, the space holding device includes first projections provided to one of the plate shape portion of the shape keeping frame and the cylindrical portion opposed thereto, and second projections with holes for receiving the first projections therein provided to the other of the plate shape portion and the cylindrical portion. The shape keeping frame is assembled with the cylindrical portion so that the first projections are inserted into the holes of the second projections to keep the inserted state by the bag shape member.
In the fuel filter structured as described above, in addition to the aforementioned features, further, the first projections and the second projections function as guides when the shape keeping frame is assembled with the cylindrical portion, and also function to allow the plate shape portion to make a parallel movement in front of the opening of the cylindrical portion when the bag shape member is bent or deformed.